[PATCH] apps: cam: Try raw role if default viewfinder role fails
Niklas Söderlund
niklas.soderlund at ragnatech.se
Wed May 7 21:34:16 CEST 2025
Hi Paul,
Thanks for your work that is now now commit ee2b011b65c6 ("apps: cam:
Try raw role if default viewfinder role fails").
I'm afraid this seems to breaks qcam for me.
arm64 ~ # ./ktool/build/src/apps/qcam/qcam -c 'imx219 1-0010'
qt.qpa.xcb: XKeyboard extension not present on the X server
There is no XRandR 1.2 and later version available. There will be only fake screen(s) to use.
[0:31:31.233222393] [794] INFO IPAManager ipa_manager.cpp:137 libcamera is not installed. Adding '/root/ktool/build/src/ipa' to the IPA search path
[0:31:31.237485661] [794] WARN IPAManager ipa_manager.cpp:148 No IPA found in '/usr/local/lib/libcamera'
[0:31:31.238603349] [794] INFO Camera camera_manager.cpp:326 libcamera v0.5.0
/usr/include/c++/14.2.1/bits/stl_vector.h:1130: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](size_type) [with _Tp = libcamera::StreamRole; _Alloc = std::allocator<libcamera::StreamRole>; reference = libcamera::StreamRole&; size_type = long unsigned int]: Assertion '__n < this->size()' failed.
Aborted (core dumped)
The gdb tracenack points to MainWindow::startCapture() and if I revert
the commit it seems to solve the problem.
arm64 ~ # ./ktool/build/src/apps/qcam/qcam -c 'imx219 1-0010'
qt.qpa.xcb: XKeyboard extension not present on the X server
There is no XRandR 1.2 and later version available. There will be only fake screen(s) to use.
[0:28:16.505731015] [746] INFO IPAManager ipa_manager.cpp:137 libcamera is not installed. Adding '/root/ktool/build/src/ipa' to the IPA search path
[0:28:16.509698783] [746] WARN IPAManager ipa_manager.cpp:148 No IPA found in '/usr/local/lib/libcamera'
[0:28:16.510769671] [746] INFO Camera camera_manager.cpp:326 libcamera v0.5.0
[0:28:16.689332683] [746] INFO Camera camera.cpp:1205 configuring streams: (0) 3280x2464-XRGB8888/Rec709/Rec709/None/Full
Zero-copy enabled
.... viewfinder displays live images ....
I have tested without the -c 'camera' option too, I then get the GUI to
select a camera. And then the same crash as reported above with -c
'camera' provided.
If I however force a viewfinder role as such,
arm64 ~ # ./ktool/build/src/apps/qcam/qcam -c 'imx219 1-0010' -s role=viewfinder
I get a functional viewfinder again.
On 2025-04-23 18:12:08 +0900, Paul Elder wrote:
> cam currently defaults to the viewfinder role when no role is specified.
> This means that on platforms that only support the raw role (such as a
> raw sensor with no softISP on a simple pipeline platform),
> generateConfiguration() would return nullptr and cam would bail out.
>
> At least this is what is supposed to happen based on the little
> documentation that we have written regarding generateConfiguration(),
> specifically in the application writer's guide, which is probably the
> most influential piece of documentation:
>
> The ``Camera::generateConfiguration()`` function accepts a list of
> desired roles and generates a ``CameraConfiguration`` with the best
> stream parameters configuration for each of the requested roles. If the
> camera can handle the requested roles, it returns an initialized
> ``CameraConfiguration`` and a null pointer if it can't.
>
> Currently the simple pipeline handler will return a raw configuration
> anyway (if it only supports raw) even if a non-raw role was requested.
> Thus cam receives a raw configuration instead of a nullptr when no role
> is specified and viewfinder is requested.
>
> However, in the near future, support for raw streams with softISP on the
> simple pipeline handler will be merged. This will notably change the
> behavior of the simple pipeline handler to return nullptr if a non-raw
> role was requested on a platform that only supports raw. This is proper
> behavior according to documentation, but changes cam's behavior as it
> used to capture fine with no parameters but will no longer be able to.
>
> Technically this is an issue with the roles API, as we are mixing
> roles in the sense of "configuration hints" (eg. viewfinder vs recording
> vs still capture) with roles in the sense of "platform capabilities"
> (raw vs everything else). In the long term the proper solution is to
> rework the roles API.
>
> In the meantime, fix cam so that it will try the raw role if the default
> viewfinder role returns no configuration. cam is an app that is capable
> of using the raw stream, so this is appropriate behavior. If roles are
> specified, then do not retry, as in this situation the user knows what
> streams they can use and what they want.
>
> Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>
> ---
> src/apps/cam/camera_session.cpp | 29 +++++++++++++++++++++++++----
> src/apps/common/stream_options.cpp | 3 +--
> src/apps/qcam/main_window.cpp | 3 +++
> 3 files changed, 29 insertions(+), 6 deletions(-)
>
> diff --git a/src/apps/cam/camera_session.cpp b/src/apps/cam/camera_session.cpp
> index 97c1ae44995e..f63fcb228519 100644
> --- a/src/apps/cam/camera_session.cpp
> +++ b/src/apps/cam/camera_session.cpp
> @@ -62,11 +62,32 @@ CameraSession::CameraSession(CameraManager *cm,
> return;
> }
>
> - std::vector<StreamRole> roles = StreamKeyValueParser::roles(options_[OptStream]);
> + std::vector<StreamRole> roles =
> + StreamKeyValueParser::roles(options_[OptStream]);
> + std::vector<std::vector<StreamRole>> tryRoles;
> + if (!roles.empty()) {
> + /*
> + * If the roles are explicitly specified then there's no need
> + * to try other roles
> + */
> + tryRoles.push_back(roles);
> + } else {
> + tryRoles.push_back({ StreamRole::Viewfinder });
> + tryRoles.push_back({ StreamRole::Raw });
> + }
> +
> + std::unique_ptr<CameraConfiguration> config;
> + bool valid = false;
> + for (std::vector<StreamRole> &rolesIt : tryRoles) {
> + config = camera_->generateConfiguration(rolesIt);
> + if (config && config->size() == rolesIt.size()) {
> + roles = rolesIt;
> + valid = true;
> + break;
> + }
> + }
>
> - std::unique_ptr<CameraConfiguration> config =
> - camera_->generateConfiguration(roles);
> - if (!config || config->size() != roles.size()) {
> + if (!valid) {
> std::cerr << "Failed to get default stream configuration"
> << std::endl;
> return;
> diff --git a/src/apps/common/stream_options.cpp b/src/apps/common/stream_options.cpp
> index 99239e07e302..288f86530351 100644
> --- a/src/apps/common/stream_options.cpp
> +++ b/src/apps/common/stream_options.cpp
> @@ -42,9 +42,8 @@ KeyValueParser::Options StreamKeyValueParser::parse(const char *arguments)
>
> std::vector<StreamRole> StreamKeyValueParser::roles(const OptionValue &values)
> {
> - /* If no configuration values to examine default to viewfinder. */
> if (values.empty())
> - return { StreamRole::Viewfinder };
> + return {};
>
> const std::vector<OptionValue> &streamParameters = values.toArray();
>
> diff --git a/src/apps/qcam/main_window.cpp b/src/apps/qcam/main_window.cpp
> index d2ccbd2318fa..224a7e5a693a 100644
> --- a/src/apps/qcam/main_window.cpp
> +++ b/src/apps/qcam/main_window.cpp
> @@ -356,6 +356,9 @@ int MainWindow::startCapture()
>
> /* Verify roles are supported. */
> switch (roles.size()) {
> + case 0:
> + roles[0] = StreamRole::Viewfinder;
> + break;
> case 1:
> if (roles[0] != StreamRole::Viewfinder) {
> qWarning() << "Only viewfinder supported for single stream";
> --
> 2.47.2
>
--
Kind Regards,
Niklas Söderlund
More information about the libcamera-devel
mailing list